One common form of sign-forming plaque heretofore manufactured comprises a relatively thin, indicia-bearing front layer of material which is laminated to a rigid, generally brittle self-supporting sign body which cannot be cut by use of a shearing device. Sometimes adhesive strips are adhered to the rear of the sign body to secure the same to a smooth vertical wall surface. Since it is extremely difficult to precisely align these adhesive strips to the edges of the sign body in mass-production manufacture, they are generally positioned on the sign body slightly inwardly offset from the margins thereof. This leaves an unsightly gap when the plaque is secured to a vertical wall surface. There is also a problem in precisely aligning the thin indicia-bearing front layer with the margins of the rigid sign body. Typically this relatively thin indicia-containing layer is initially made of a larger size than the sign body, so that after the indicia-carrying layer is applied to the sign body it is trimmed as evenly as possible to coincide with the margins of the sign body.
The individual effort needed to assemble such a plaque is quite substantial, and mass production thereof was considered impractical. Because of the unique construction of the plaque of the present invention and the method of making the same, sign-forming plaques of types that mount on a vertical support wall, or types which can be stably supported on a horizontal support surface or hung from the ceiling, can be mass produced in a very expeditious inexpensive way.